Checkerboard: A Regular Structure and its Synthesis

A regular circuit structure called a Checkerboard (CB) is proposed. In some CB configurations, all mask layers except the via layers are pre-designed, which is attractive for high manufacturability and performance predictability and for lowering mask costs. The synthesis algorithms developed for the CB makes use of their structural regularity and flexibility. No technology mapping is needed; placement and routing are integrated. Experimental results are favorable for CB up to about 10k gates, compared to other structures such as standard cells. For example, the Vk-CB version of CB uses on average only about 4% more area but is 8% faster.